Thyroid

Thyroid storm

The treatment of thyroid storm includes the following:

1.Blockade of peripheral effects with β-adrenergic agents

Propranolol is the drug of choice to block peripheral effects of thyroid hormone because it has the additional benefit of slowing the peripheral conversion of T4 to T3. If a contraindication to propranolol exists (eg, asthma, congestive heart failure), then a selective agent such as esmolol may be used.esmolol does not have intrinsic membrane-stabilizing activity and therefore does not inhibit the peripheral conversion of T4 to T3.

2.Blockade of synthesis with propylthiouracil (PTU) or methimazole

PTU blocks the enzyme thyroidal peroxidase to inhibit thyroid hormone synthesis. It is generally preferred over methimazole because it also inhibits the peripheral conversion of T4 to T3.

3.Blockade of release with iodine or lithium

Blocking release of thyroid hormone is best accomplished with iodine, but lithium can be used in iodine-allergic patients. It is important not to administer iodine until the synthetic pathways have been blocked with PTU, otherwise administration of iodine might cause more thyroid hormone to be formed.

4.General supportive care, including cooling blankets and corticosteroids.

Administration of glucocorticoids is recommended because thyroid storm can precipitate adrenal crisis (relative adrenal insufficiency). The dose is the same as for adrenal crisis. Dexamethasone is the preferred agent because it also blocks the peripheral conversion of T4 to T3. Empiric antibiotics should be considered in patients with thyroid storm when infection is also suspected, but they should not interfere with the administration of propranolol, PTU, iodine, or dexamethasone.